Immunodeficiency is a state in which the immune system’s ability to fight infectious disease is compromised or entirely absent. As Prof. Hans-Hartmut Peter (University Hospital Freiburg) describes in his editorial, published in Arthritis Research & Therapy, there are increasing numbers of patients with symptoms of a dysfunctional immune system being seen in rheumatology clinics. Symptoms include recurrent bouts of fever, frequent and prolonged infections, unusual pathogens, hepatosplenomegaly and recurrent mucocutaneous candidiasis.

The important question is: who is best suited to take care of these patients? In Prof. Peter’s opinion, “modern rheumatology, with its intricate links to clinical immunology, is the medical discipline best prepared to follow these patients and organize a close consultation platform with other disciplines, notably hematology, infectious disease and pathology.”

The ‘Adult immunodeficiency’ series of six review articles published in Arthritis Research & Therapy brings the latest developments to a rheumatology readership, with the aim of directing the field deeper into clinical immunology and novel strategies of targeted therapies.

“Rheumatologists will profit from an increased awareness of two important areas of recent discoveries: first, a series of gene defects leading to deregulated IL-17 responses in chronic mucocutaneous candidiasis reviewed by Gaffen’s group; and, second, the crucial importance of mutations in the signal transduction molecules STAT3 and DOCK8 in hyper-IgE syndrome reviewed by Yong and colleagues.”

Genetic contributions to another hyperinflammatory disease, hemophagocytic lymphohistiocytosis (HLH), are described in the review article from Stephen Ehl’s research group. HLH is characterized by activation and massive proliferation of T cells and macrophages, leading to marked hypercytokinemia.  Untreated primary HLH is rapidly fatal within a few weeks, so prompt and adequate treatment is vital for a positive outcome.  Bode and colleagues explore the important advances in therapy, including immunochemotherapy and hematopoietic stem cell transplantation.

Remarkable scientific progress has also been made on hyper-IgM syndromes and hypogammaglobulinemia/common variable immunodeficiency, as described in the remaining three expert articles in this review series. Immunodeficiency is thus a booming field of translational immunology that has many cross-disciplinary linkages and should not be ignored by the rheumatologist.